I have noticed that many of the early posts on this blog get relatively little traffic, so I have decided to start republishing some of them.
This is a typically ridiculous Cassidy claim. Scholars have quite rightly identified that this word is Germanic in origin and is linked to the Dutch word busen, which meant to drink to excess. Booze is a long-established word in English, both as a verb and as a noun. For example, searching on the Michigan Middle English Dictionary website, I found this, from around 1325: Hail, ȝe holi monkes..Late and raþe ifillid of ale and wine! Depe cun ȝe bouse. (Hail, you holy monks. Late and early filled with ale and wine! Deep can you booze.)
Cassidy disagrees. On the basis of his vast knowledge of the Irish language (!) he believes that this word derives from an Irish word beathuis. Now, you will search in vain for this word in the dictionary. Beathuis is not a real word. Even if it were real, it wouldn’t sound much like booze. It would be pronounced as bahish.
Where did Cassidy get this word? Well, there is a word beathuisce (life-water) in the dictionaries. It is a variant of the vastly more common uisce beatha (water of life) which is the origin of English whisk(e)y. This variant seems to be found mostly in songs and poems and is probably used in these contexts for reasons of metre, because it has 3 syllables rather than 4. It is pronounced bahishka. So what about the inconvenient –ka at the end? After all, nobody talks about boozeka in English! According to Cassidy, beathuisce was shortened to beathuis. He gives no evidence of this or reason for it, and it seems about as likely as someone in English contracting the word water to wart.
So, to recap, there is a perfectly good derivation from Dutch which fits the facts, sounds right and has the right meaning, and was established in English by the early 14th century. And there is a completely improbable candidate which doesn’t sound like booze and which was made up by Cassidy by mutilating a rare variant word beathuisce, the ‘word’ beathuis.
Which is correct? I’ll leave you to make up your own mind on that one!